Impeovement est deills fob wells



uitrit tutes getraut @HittI IMPROVEMENT 1N Dents ros WELLS. i

HENRY w. SAFFORD, or PHILADELPHIA, PENSYWANIA. f

' LeaersPafmNo. 60,261, ma Deetman, 1866. i

SPECIFICATION. .y TO ALL WHOM VIT MAY CONCERNE i Be it known that I, HENRY W. SAFFORD, of the city of Philadelphia, in theState of Pennsylvania,` have i i invented a new and useful Improvement inthe Drill or Reamer used in boring deep Wells and I do hereby@` declare that the following is a full, clear, and exact description of the construction and operation of `the same, i l i reference beinghad `to the accompanying drawing, making a part of this specification, andto 'the letters `oi" reference marked thereon.

In the operation ofboring petroleum and other deep wells, it frequentlyhappens that the shank or stem of" `I i Q the drill, centre-bit, or reamer used for the purpose, breaks across or parts at theusual weld, just below the screw and boss whereby it is fastened to the lower end of the op,erating-shaft,and,consequently it often becomes p u impossible to withdraw from the well the lower or cutting end of `the said 'tool without weeks of ,labor anda heavy `expenditure of money; and in many cases of petroleum wells nearly finished, the` wellhas to be wholly `I .p abandoned, at a loss 'of thousands of dollars, in consequence of the broken tool therein,` and a` new well i commenced.

The object of my invention is to provide against this very serious diculty in boring petroleum and other i deep wells; and it consists in providing. the said drill, or other tool used for the purpose, with a supplementary boss or projecting shouldenwelded or otherwise xed around on the shank or stem of thesaid too1,"at any suitable point below the said weld, so that if,` in boring or-drilling at any depth,` the weld part,` or the shank or stem, break above the said supplementary boss, there will not be any difficulty in withdrawing the lower or cutting end of the said tool, as the saidisupplementary'boss thereon will afford an appropriate head beneath i.

which the usual grappling-irons will close on the shank, and thus enable the operator to withdraw the brokena "off end of the tool with the greatest facility and certainty. i i i i AIn the drawing, A B represents a common drill used in boring petroleum wells; a beingthe screw, and a ,p the boss or shoulder which abuts against the lower end of the usual operating-rod, (not shown in the drawing,)to`

which the tool must be screwed fast; a3 is called the shank `or stem; the lower or `cutting end, a, of 1the tool being usually welded to the upper end at the point markedbypthe dotted diagonal line y and `bl is the supple` mentary boss or shoulder. The supplementary boss b1 is simply an iron bandfwelded around on the shank ai,

so as to produce a surrounding offset or shoulder at a suliicient distance below'the weldingline zig, not to. interfere with the welding operation which a break may, at any time, requirerto be performed. In boring-deep we lls, the tools always break at or near the weld x y, the weld sometimes parting, and it willbe, seen that, lin either case, the supplementary boss bTL will enable the operator to withdraw the cutting end of abroken tool from the well, immediately, andwthout any diiculty, by the useof the usual grappling-irons. The thingie very simple, but nevertheless new and important in its application forthis purpose.. Old drillers say it will save thousands of dollars in boring deep wells; and my own experience in the art satisfies me that it will` hereafterbe considered absolutely indispensable,- on the ground of economy.

Having thus fully described m improvement, what I claim as new of my invention, and desire to secure by i Letters Patent, is-

Providing the stem or shank, a3, of the drill A VIB, -or other boring or cutting tool used in` makingdeep p wells, with a iixed projecting shoulder or supplementary boss, b1, between the upper boss a2 and thecutting end l a, substantially as and for the purpose described.

" p ,v HENRY W. S.A.F]3OR1L` Witnesses;` ,p

BENI; zMoarson, Jas. Wmsuons, lJr.' 

